Participants will then have an airway interruption test to detect pressure changes in the voice box during production of continuous sounds. A nose clip is placed over the subject's nose and two sensor devices are placed on the neck to pick up changes in movement and position of the vocal cords during voicing. A mouthpiece is placed in the mouth, and subjects are asked to say "ah" continuously at a specified sound level. This voicing is repeated 33 times with periodic breaks.